Where to put fuses in a dc circuit?

Say I have a 12 volt battery and I want to connect a light and a radio.  Should I put a fuse next to the positive or negative terminal of the battery?  Or should I fuses in front of everything.  DC current flows from pos to neg right?  so I would put the appropriate fuse on the positive side of each electronic device?    

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Dr.Bill6 years ago
All my equipment is fused individually on the positive (red) wire.
If you want to fuse the Positive side wire off the battery too its OK.
frollard7 years ago
Seconded. It will work on either side, but in series with + is most common.

"current flows from pos to neg right?" -- Depends, current 'technically' flows from - to + (electronis are negative, and they are the part that moves). In the old days it was thought that there was a positive particle that moved so "conventional current" is + to -. These days many schematics use the same old symbols that indicate the direction of conventional current (transistors, diodes, etc) but it's important to understand the difference.
That is good to know man. Thanks for the help I was wandering the same thing, and its working, so I am happy with it.

Tut tut. Are you talking about majority or minority carriers ?Conduction in solid metals is by electron flow sure, but not for a lot of other things.


NachoMahma7 years ago
. Is fusing the positive side a standard (a Q&D search didn't turn anything up) or just convention?
Every fuse I've seen has been on the hot side of AC, or non-ground side of a DC circuit. Probably just convention.
Do whatever you like.
orksecurity7 years ago
Fuse goes in series with the load, to protect the power supply if the load shorts out. Positive or negative side doesn't matter; fuse responds to excessive current, not voltage or polarity.
Re-design7 years ago
In a circuit like this it doesn't matter.